Development Specs

Systematic Approach

• Collect all possible error states from functions
• assign error codes for macros?

• G_option() parameters (like output->description = ("Path to resulting ASCII file");)

How should Errors/Warnings/Messages be formatted

• strings < >
• numbers [ ]

Macros to be defined for C library

• MSG_RASTER_NOT_FOUND_IN_MAPSET - "Raster map <%s> not found in <%s>"
• MSG_CANNOT_OPEN_RASTER - "Failed opening raster map <%s>"
• MSG_CANNOT_OPEN_FILE - Cannot open file <%s>

Parameters and flags

Fix the parameters and flags. Make it a concept. See proposal in GRASS 5 documents/parameter_proposal.txt

Verbosity levels

Current abstract concept

verbose	3	MAX_LEVEL	print progress and all messages messages
standard	2	STD_LEVEL	print progress and selected messages
brief	1		print only progress information
silent but not mute	0	MIN_LEVEL	print nothing (but ERR and WAR)
mute	2>&1 > /dev/null

Proposal

• module output (should be "parsable") is not controlled by GRASS_VERBOSE [use fprintf (stdout, ...)]
• silent
  • only warnings and fatal errors are printed
• brief
  • all G_percent() and selected G_message() (especially connected to progress information, up to the programmer ??)
• standard
  • all G_percent() and selected G_message()
• verbose
  • all G_percent() + G_message()

Modification

• remove verbose level → standard == all G_percent () + G_messages()
• move some messages to G_debug()
• change level numbers to 1, 3, 5
• Add new G_msg(int level, "%format", ...); lib function. Existing G_message() could stay and would be the same as G_msg(LEVEL_STD,...).

Discussion

• HB: I'm quite happy to leave the current system as it is, but use GRASS_MESSAGE_FORMAT=silent to switch off G_percent(),G_clicker() output.

Mixing a sliding verbosity scale plus a binary switch or >= rule for when G_percent() happens in the same variable is very messy IMO.

Alternative Abstract concept

standard	3	PERMSG_MODE	print progress and messages
standard	2	MESSAGE_MODE	print only messages
brief	1	PERCENT_MODE	print only progress information
silent but not mute	0	QUIET_MODE	print nothing (but ERR and WAR)
mute	2>&1 > /dev/null